Having trouble getting new injector washers from my local 4x4 dealer, one washer is stuck in the old head and is not going to come out nicely, I removed one from another injector and it was really tough to get it off it seems to be diamond profile now, managed to find an independent injector company today unfortunately the tech is on holiday but the nearest washers we could find fit perfectly but are dished, I presume they will crush to suit both sealing faces when torqued up, anyone know if they are supposed to be dished?